GStars
    nektos

    nektos/act

    #138 this week

    Run your GitHub Actions locally 🚀

    devops
    ci
    github-actions
    golang
    Go
    MIT
    70.1K stars
    1.9K forks
    70.1K GitHub watchers
    Updated 5/4/2026
    View on GitHub

    Backblaze Generative Media Hackathon

    Build the next generation of AI media apps with Genblaze, stored on Backblaze B2. $10,000 in prizes.

    Enter the hackathon

    Loading star history...

    Use Cases & Benefits

    • Act enables running GitHub Actions workflows locally for faster feedback and testing without pushing commits.
    • Built in Go, it uses Docker to simulate GitHub Actions environments matching official environment variables and filesystems.
    • Strengths include rapid local testing and integration with VS Code; limitations may include Docker dependency and partial GitHub Actions feature support.
    • Organizations can integrate Act into CI/CD pipelines to debug workflows locally, reducing iteration time and improving developer productivity.
    • Ideal for developers and teams using GitHub Actions who want to test and debug workflows quickly before pushing changes.

    About act

    act-logo

    Overview push Go Report Card awesome-runners

    "Think globally, act locally"

    Run your GitHub Actions locally! Why would you want to do this? Two reasons:

    • Fast Feedback - Rather than having to commit/push every time you want to test out the changes you are making to your .github/workflows/ files (or for any changes to embedded GitHub actions), you can use act to run the actions locally. The environment variables and filesystem are all configured to match what GitHub provides.
    • Local Task Runner - I love make. However, I also hate repeating myself. With act, you can use the GitHub Actions defined in your .github/workflows/ to replace your Makefile!

    [!TIP] Now Manage and Run Act Directly From VS Code!
    Check out the GitHub Local Actions Visual Studio Code extension which allows you to leverage the power of act to run and test workflows locally without leaving your editor.

    How Does It Work?

    When you run act it reads in your GitHub Actions from .github/workflows/ and determines the set of actions that need to be run. It uses the Docker API to either pull or build the necessary images, as defined in your workflow files and finally determines the execution path based on the dependencies that were defined. Once it has the execution path, it then uses the Docker API to run containers for each action based on the images prepared earlier. The environment variables and filesystem are all configured to match what GitHub provides.

    Let's see it in action with a sample repo!

    Demo

    Act User Guide

    Please look at the act user guide for more documentation.

    Support

    Need help? Ask in discussions!

    Contributing

    Want to contribute to act? Awesome! Check out the contributing guidelines to get involved.

    Manually building from source

    Discover Repositories

    Search across tracked repositories by name or description